In the field of radiotherapy technique, methods for determining a dose distribution in a human tissue may broadly include two categories, including a semi-empirical analytic method and a Monte Carlo method.
The semi-empirical analytic method may include a method based on an off-axis ratio (OAR) empirical equation, a convolution/superposition method based on a pencil beam kernel and a point kernel, etc. However, the semi-empirical analytic method may have a limited accuracy.
The Monte Carlo method may be not substituted due to a capability of solving complex problems (e.g., complex geometry, a complex arrangement of a radiation source, etc.). The Monte Carlo method may be used to establish models relating to a physical process accurately with less approximation in a radiotherapy. The biggest disadvantage of the Monte Carlo method may be its large computational strength and time-consuming.